<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title>online</title>
	</head>
	<body>
		<script>
			var xhr = new XMLHttpRequest()
			xhr.open('GET','time.php')
			xhr.send(null)
			
			// onload 是 HTML5 中提供的 XMLHttpRequest v2.0 定义的
			xhr.addEventListener('load',function() {
				console.log(this.readyState)
				console.log(this.responseText)
			})
		</script>
	</body>
</html>
